Spins extracted from fermionic states and their entanglement properties
Phys. Rev. A 112, 012808 – Published 14 July, 2025
DOI: https://doi.org/10.1103/ktdz-rsjm
Abstract
We investigate the spin states obtained by extracting electrons from closed-shell fermionic states. A partition of the system is defined through the introduction of the extraction modes. We derive the expression of the -body reduced density matrices, which represent the extracted spin states. We show that these states exhibit different forms of spin entanglement, whose detection is discussed in terms of the spin-squeezing inequalities.